Beginner White balance quandary.

[UaeExile]

'cos jpegs store colours in 8 bits rather than 12-16 and are compressed at that. When you tweak the colours - i.e. apply a curve to them - you'll lose still more information. It doesn't take much before you can see banding in one or more of the colour channels, especially if you do any further processing.

Applying a WB correction to a jpeg is a destructive operation; when you do it to a raw file it happens immediately after demosaicing.

Makes sense. Thanks Simon.

 

[sk66]

Take a look at these two screen grabs. The first is a 16bit edit, and the other is an 8bit (jpeg) edit... pay attention to the histograms. Exact same edit applied...